Carbonate rock aggreate bonded with bitumen containing a polyalkylene polyamino imidazoline



United States Patent CARBONATE ROCK AGGREGATE BONDED WITH BITUlVlEN CONTAINING A POLYALKYLENE POLYAMINO IIVIIDAZOLINE Charles M. Blair, Jr., Webster Groves, and Kenneth J. Lissant, Kirkwood, Mo., assignors to Petrolite Corporation, a corporation of Delaware No Drawing. Application December 21, 1950, Serial No. 202,138

8 Claims. (Cl. 106273) ((LHANX) m (1) where R is a hydrocarbon radical containing from 8 to 32 carbon atoms; X is hydrogen or a small alkyl radical such as methyl, ethyl or propyl, and m is the number 3 to 10. These compounds and groups will be more completely described below, along with a description of the preferred types of compounds of this class, for use in improving the anti-stripping properties of bitumen and aggregate compositions. In a further aspect the inventionnot only includes the use of the imidazolines as such, but also their salts, as hereinafter described.

A specific phase of the present invention is the use of the imidazolines, and more particularly, certain salts of the imidazolines, in connection with aggregates which have a carbonate structure, such as limestone, dolomite, etc., as differentiated from aggregates which are largely siliceous, such as quartz, sand, rhyolite, granite and the like.

In many industrial applications of bitumen, asphalt, tar and similar asphaltic or bituminous produces, these materials are mixed with or applied to inorganic materials to form a concrete-like composition which is utilzed for the preparaton of roads, dams, runways and other structures, or surface coatings where mechanical strength and impermeability to water or moisture are im portant functions. The most familiar application involving asphalt or bituminous materials mixed with inorgamc products, is in the preparation of asphalt roadways. In this case, the inorganic material is referred to as aggregate, and the bituminous material is used for cementing the aggregate and retaining it in a smooth continuous form. Other applications include those in which asphalt is employed in compacting of earth to retain or direct the flow of water, in the preparation of airport strips and n the compacting of soil to prevent erosion. The inorganic material associated with such asphalt or bituminous products is usually either siliceous rock such as river gravel, crushed granite, rhyolite or the like, or crushed limestone, dolomite, or, in some cases, ordinary earth. Another familiar application of asphalt to inorganic material is in the coating of pipes or metal structures with bitumen or asphalt to protect the metal from corrosion.

.It has been found in practice thatwhen asphalt is iCQ mixed with or applied to such inorganic materials, the concretes and coatings so formed are, in many cases, badly attacked by water, so that the asphaltic binding agent is actually separated from the rock or metal by moisture, with consequent decrease in strength, and, in some cases, actual washing 01f of the asphalt. This apparently arises from the fact that some asphalts or bitumens do not wet many of the aggregate materials used sufiiciently well to prevent stripping by moisture.

We have found that by addition of certain organic reagents to the asphalt or bituminous material in relating agents may also be applied first tively small amounts, the ability of the asphalt to wet inorganic aggregates is greatly increased, and that asphaltic cements prepared from asphalts containing such organic materials are highly resistant to leaching or stripping of the asphalt when the cement is in contact with moisture. Materials having this property are sometimes referred to as asphalt wetting agents, and a particular class of compounds herein described may be said to have asphalt wetting properties to a high degree. These wetto the inorganic material to enable it to be readily wet by the asphalt.

The entire rationale underlying the effectiveness of additives of the kind herein described is not entirely understood, for the following reason: To the extent that the hot fluid or liquid asphaltic material wets the inorganic aggregate or equivalent more readily, in the same sense that an aqueous solution of a surface-active agent wets an oily surface more readily, one may consider the function of such additive as being a wetting agent in the sense that it increases the wettability or tendency of the non-aqueous vehicle to wet or coat an inorganic substance.

However, some bitumens, asphalts, etc., seem to have natural wetting properties, but yet are susceptible to being stripped off readily, due to the action of moisture, as described in greater detail subsequently. It thus becomes apparent that perhaps the most significant property of these additives is their ability to prevent stripping in the solid state, or substantially solid state, which results from cooling, the resolution of an asphalt or bitumen emulsion, or evaporation of solvent from an asphalt soin adherence and bonding of asphaltic,

lution. Stated another way, there are instances wherein the-presently described additives might not confer any wetting property whatsoever, and yet be of enormous importance, due to the anti-stripping property.

In light of what has been said previously, it is customary in the trade to refer to these particular additives as anti-strippers or anti-stripping agents even though they could be designated as Wetting agents or binding agents in the peculiar sense previously noted.

According to the present invention, this improvement bituminous, tarry and hydrocarbon products to aggregate rocks and metals, 1s accomplished by adding to the bituminous material or to the aggregate, a relatively small amount of a high molecular weight polyaminoimidazoline having at least 3 amino groups in the l-nitrogen atom substituent. These compounds are basic, heterocyclic ring compounds.

The preparation of an imidazoline substituted in the 2-pos1tion by aliphatic hydrocarbon radicals, is well I described -in;the literature and is readily carried out by For the preparation of reagents suitable for the present invention, One may react a polyethylene amine containing or more amino groups, at least one of which is a primary amino group separated by 2 carbon atomsfrom another primary or a secondary amino group. For example, if one reacts one mole of tetraethylene pentamine with one mole of stearic acid, at a temperature ofv 250-290 C, a substantial yield of polyaminoimidazoline is formedas illustrated by the following equation:

POIyamines which are suitable for the synthesis of the polyaminoimidazolines of the present invention, include tetraethylene pentamine; pentaethylene he'xamine, tetra: isopropylene pentamine; higher boiling polyethylenepoly amines obtained, in the manufacture of tetraethylene pentamine; N-ethyl, tetraethylene'pentamine; l-(triethylenetriamino), 2-diaminopropane and the like. Similar suitable polyamines may be obtained by condensation of dior polyarnines with ethylene dihalides; 1-,2 propylene dihalides; and other 1,2 alkyl dihalides. For exampl'e, a: suitable high boiling polyamine was prepared byheating together two moles of diethylene triamine with one: mole of ethylene dibromide. Heating was carried: out. at. 100 C. and held at this temperature by cooling after, reaction started. It was then maintained at this temperature for 4 hours after the reaction. subsided. The resulting polyamine hydrobromide was utilized directlyin the-v imidazoline'synthesis with abietic acid, yielding a polyamino imidazoline hydrobromide.

Similar suitable polyamines may be obtained by condensation of 1,2 diaminoalkanes with 1,2 dihaloalkanes. Theresulting polyamino salts may be used as such, or may be converted-to the free polyamines by neutralization with, for example, concentrated NaOH, heating to remove water, and filtering to remove salt. In such synthesis, of course, a variety of. alkylation reactions take place with the production of a mixture ofpolyamines which may subsequently be distilled or otherwise fractionated to obtain a high molecular weight fraction having 5 or'more amino 'groups per: molecule and with the requiredlprimary and secondary amino groups. The imidazoline' formation reaction can, itself, be used-to assay such crudepolyamine mixtures for content of suitable species of amines capable of yielding imidazolines by reaction-withcarboxylic acids.

Acids suitable'for this type of synthesis-include the aliphatic acids such as oleic, linoleic, linolenic,'stearic, and erucic, as well as other carboxylicacids such astall. oil acids, abietic acid, naphthenic acid,-cycloh'exyl"propionic'acid, naphthylacetic acid,'and the-like. For-each Stearic acid Tetraethylerie pentamine general, the amount of such oxygen, in comparison with 'th'e'totalweight of the group, is small and its presencewill have relatively little, if any, eifect on the general properties of the resulting imidazoline, and for all practical purposes, such acids can, be used in the same way in which one would employ other carboxylic acids in preparing products employed in this invention. In the appendedclaims when referenceis' made to a-hydroca'rbon substituent in the 2-positi'on of an imidazoline ring, we intend. to include the residue ofv-suchhy droxy'acids and. ether acids,,and when reference is made to the residue-of a fatty acid as a substituent of the-lsposition offithe imidazoline ring, we intend to include the residues of such acids as'i'ici'noleic acid and h'ydroxy stearic acid. These are recognized as being the obvious functional equivalents of the other fatty acids which do not contain such a hydroxyl group for the herein stated purposes.

One may also employ esters of the above; mentioned carboxylicacids in i'rnidazoline synthesis, as has been pointer; out. in the literature. cited. For example,xone-, might employ'ethyl stearate in place of the stearic acid" slr'own i'nthe: example above. In suchiustance, one'mole of water. and one mole. of ethanol areevolved duringithe: reaction... Where the ester of. a high boiling; or non-- volatile alcohol is used, the alcohol formed during the reaction will main in the product. Usually, the amount of such alcohol constitutes a relatively small proportion of the product and may be left therein without seriously afiecting its properties, as regards its utility in the present invention.

The condensation of carboxylic acids with ptolyamines to form aminoimidazolines, is usually carried out at a temperature of about 250 C. to 290 C. at atmospheric mole of aminoirnidazoline product, one mole of carboxylic' acid having at least 9 carbon atoms and not over 33 carbon atomsmust be employed in order-to obtain a'product containing'a-hydrocarbon-group of fronr8' to 3'2'carbon atoms substituted -in the 2-position of one of the imidazoline rings.

Other acids'suitable for use in imidazoline synthesis include many which contain oxygen other than that occur= ring as a portion of the carboxyl group. Examples of these are butylphenoxyacetic acid, ricinoleic acid, hyd'roxystearic acid, dihydroxystearic acid, hydroxy acids obtained by the oxidation of paraffin and high melting'point microcrystalline waxes, aryl stearic acids such as are obtainable by condensation of phenol or alkylated phenol with oleic acid, and the like. When such acids as these are employed in imidazoline synthesis, the substituent of the Z-carbon atornof the imidazoline ring will contain the ether or hydroxyl group. oxygen present in the-originalacid; In"

pressure. By carrying out the process under a partial. vacuum, reaction maybe completed at somewhat lower temperatures. Completeness of reaction may be determined, by measurement of the, amount of. water evolved during reaction- Usually, a small, amount of ammonia or, ,other' low boiling bases is evolved during the reaction, as the result ofa minor amount, of decomposition ofIthe polyamine,particularly when the reaction is carried out at. temperatures-of 275-290 C. Allowance for the weight of such volatile material must be madein esti-v mating the quantity of evolved water in thecondensate from -the. reaction.

As.pointed out previously, in Formula 1, the-rings car bon.;atoms.'oitheimidazoline, and the, amino groups. forminga part of the l-substitutent, may havealkyl group-substit-uents. The nature and location of. these.

groups is deterrnined'by the choice of reactant poly-- amine. p

--For example, it one reacts stearic acid and'Z-triethyl:

eneetetr-amino-l aminorpropane, a substantial. portion of.

theiproduot; results: from the following reaction:

oiirrafoo'o'ia a arm.onzdrmnioimnn n Ibis-seen that the: S-carborr atom of the: imidaZoline -ring;

has' a methyl group: 'sub'stituent. If one employs lrtfi" ethylene tetramino;leamino-butanc as. the. po-lyaminetres actant, the S-carbon' atomaof' the ringhas an cthyli group substituent'; Sin-Iilarly; the: 4 -carb1on:-atom*of. the. ring may-have analkyl substituent, where :the polyaminea re: 'abtanfcontains: an alkyl substituent on the: carbon=- atom attached to'-a='primary aminozgroupa In the' above example of reaction between stearioracid and 2-triethyleneatetraminoaleamino-propane, the: j poly-- amine reaotan-t'conta-ins two primary amino; groups'sep by twocarbon atoms :from a secondary anunov group. -'-,,'l hus;-the reaction between these compounds may carbon atoms.

proceed to formation of a polyamino imida zoline by two routes, the first illustrated above, and the second proceeding as follows:

From the above description of the reactants used and the method of preparation employed, it is evident that the most general formula for the broad class of polyaminoimidazolines employed in the present invention is that of Formula 1, namely:

where R is a hydrocarbon radical containing from 8 to 32 carbon atoms and X is hydrogen or an alkyl radical, generally containing less than 4 carbon atoms, and m is the numeral 3 to 10.

We have found that the polyaminoimidazolines having 3 or more amino groups in the substituent of the 1-nitro gen atom of the imidazoline radical, are particularly 'effective anti-stripping agents, showing activity consider ably greater in this respect, than could be predicted from the behavior of imidazo lines having 2 or feweramino groups the l-nitrogen substituent. We prefer, particularly,the-polyirnidazolines containing from 4 to amino groups.

Polyaminoimidazolines, which we particularly prefer to use,'because of their unusual activity as anti-stripping agents and the availability of raw materials'for their preparation, are those corresponding to the formula:

where the symbols R and m have their previous meaning. It is" to be noted that these products correspond to those of Formula 1, where X is hydrogen. These compounds are readily prepared from unsubstituted polyethylenepolyamines having 5 or more nitrogen atomsv per molecule. I

Further compounds of special interest are those of Formula 2, wherein R is the hydrocarbon residue of a ,fatty or 'resinacid and contains at least 8 and not over 20 Such compounds represent particularly cheap and effective anti-stripping agents,- and cah'bel acid, stearic acid,;

synthesized from acids such' as oleic rosin, abietic acid and tall oil acids.

As examples of suitable and particularly etfectiveantistripping agents, the following are presentedi EXAMPLE 1 I n v 326 gms. of commercial tall oil (saponification value of 172 mg. KOH/ gm.) was mixed with 232 gms.; of crude' high boiling polyethylene polyamine which" assayed 36.0% nitrogen. This would correspond closely in nitrogen content to an average molecular composition I of:

NH2(C2H4NH)5H. This mixture was placed in a13-neck,"

round bottom flask, fitted with sealed stirrer, thermometer;

water trap and condenser. While stirring, the -reactantsv were slowly brought to 280 C., andheld for.3..ho urs. During this period, 1.8 moles of water were collected in. the trap, along with about 6 ml. of an oily liquid.

EXAMPLE 2 326 gms. of tall oil was reacted, as in Example 1, with 218 gms. of a polyethylenepolyamine assaying 32.6%

nitrogen and consisting largely of monoethyltetraethylenepentamjne.

EXAMPLE 3 242 gms. of Oronite Chemical Company Naphthenic:

Acid L (one mole) was reacted as in Example 1, With 189 gms. of tetraethylenepentamine.

EXAMPLE 4 284 gms. of stearic acid were reacted with the poly-j amine of Example 2, employing the procedureand equip-i ment of Example 1.

EXAMPLE 5 284 gms. of stearic acid and 189 gms. of tetraethylenepentamine were reacted as in Example 1.

EXAMPLE 6 326 gms. of tall oil and 189 gms. of tetraethylenepentamine were reacted as in Example 1.

EXAMPLE 7 302 gms. of abietic acid were reacted, as in Example 1,:

EXAMPLE 8 320 gms. of tall oil acids were reacted, as in Example 2,:

with gms. of Carbide & Carbon Company Polyamine H, a polyethylene polyamine still residue assaying. 31.9% nitrogen and boiling above tetraethylene pentamine.

Although we have described the presentanti-s'trippihg' agents of polyaminoimidazolines, we may, in many instances, employ these compounds in the form of their salts, either with organic or inorganic acids. Being rela-' tively strong polyacidic bases, they readily form-a variety of salts, depending upon the extent of neutralization. Ex-' amples of acids which may be used to form such salts are' hydrochloric, sulfuric, sulfamic, acetic, oxalic, oleic, stearic, tall oil, rosin, abietic, maleic, naphthenic, glycol lic, phenylacetic, benzoic, etc. V 3 7 i Salts of the polyaminoimidazolines are effective anti-L stripping agents as well, and in someinstances, exhibit better solubility in cut-back asphalt, or solvents inwh'ichthey are to be applied to rock or other aggregate.

The products of the present invention are generally effective in preventing the stripping of asphalt when in corporated therein in concentrations within the range of about 0.05% to 2%. The amount required depends, in any particular case, upon the nature of the asphalt, the temperature of cure, the kind of surface coated, and perhaps other variables not completely known. In actual practice, the required amount of reagent to prevent strip pingjs; often estimated; by laboratory'tests. withthe as, phaltic composition, and the aggregate. of immediate interest.

The: effectiveness of the present. reagents inpreventing stripping is illustrated by the results of laboratory stripping tests such as are shown in Table I below. This test was conducted as follows:

100 gramsofi State ofYirginia. siliceous test aggregate was placed in a OIICrPiIlt. wide-mouth jar. Two gramsoiwater were added, to the aggregate, the jar was closed and the. contentsnfixed. by rotating the jar on a roller mill for Zminutes. To the thoroughly wetted aggregate was-then; added. 4 grams of .R.C.-3 cut-back Mid-continent asphalt containing aknown amount of the. anti-strip additive; This mixtnre; wasrolled on the. mill for 30 minutes; afterwhich 250ml. ofdistilled water were added torthe. jar, The contents were then mixed. for. one hour on the mill. The jars werethen .righted and allowed to stand 30 minutes, following which the Water and any floating asphalt were decanted from the jar. The aggregate: was then dropped onto clean filter paper, allowed to drain and;dry at-room.temperature, and finally inspect.- edlfor percentage of surface stripped.

For comparison, the results are also givenfor; a num: ber of imidazolines, and for aminoimidazolines having only one or two amino groups in the lnitrogen substituent;

These conditions simulate the worst type of conditions to be encountered in road building, i. e., those requiring coating of a wet aggregate withajheavy rain falling on thefreshly laid road surface. Under these conditions of test, s.tripping of less than about 20% is considered as indicating an effective reagent and concentration.

The particular etiectivenessof the products described hereinisrtobennoted, particularlyv at low and intermediate-concentrations.

While, in the experiment described. above, the. antistripping agent was added to the asphalt. solution, other methods, of application areequally eiiective. The reagent .may be: dissolvedin water or other solvent and appliedto the aggregate .before contacting with the asphalt, Where .it, is. desired to use. an aqueous solution itisfirequently advisable to employ the reagent. as a salt, for example, asthe acetate, chloride, or sulfate, in which form it is more likely to be easily water-soluble or dis.- persible. When used in oilsolution, salts may be-used also, as,,.for example, the .acetate, oleate, sulfate, or stcarate.

Alternatively, the undilutedreagent may be applied to the rock or other surface by spraying, dipping or milling, preferably while hotv and thus low in viscosity.

When employed in emulsified asphalts, the reagent mayhe added directly to the emulsion, or may be incorporated. in the .asphaltor water prior to emulsification.

WeUhave found that certain, salts of the polyamino imidazolines are superior in anti-stripping properties to the unneutralized .po1yaminoimidazoline. These salts are the; completeor partial saltsprepared by the addi: tion otmonocarboxy, detergent-forming acids, contain: ing from 8 to 32 carbon atoms, or polymeri fisl, detergentforming, carboxy acids containing from 8 to 32 carbon atoms per carboxyl group. Examples of suitable monocarboxy, detergent-forming acids. are. octoic acid". oleic; acid, palmitic acid, stearic acid, linoleic acid, erucic acid, tall oil fatty acids, abietic acid, ricinoleic acid, rosin, 'naphthenic acid, oxidized wax acids, phenylstearic acid, and the like.

Examples of polymerized, detergent-forming acids suitable for neutralization or partial neutralization of the present aminoimidazolines to improve their anti-stripping action, are the dimeric and trimeric linoleic acids, such as are described by Goebel, Journal of American Oil. ChemistsSociety, 2.4, 65. (1947), the corresponding acids. from oleicacid and linolenic acid, polymerized rosin. polymerized abietic acid, and the like. For the preparation of polymerized rosin or abietic acid, see c. g. U. S. Patent No. 2,515,218, dated July 18,. 1950, to Hampton.

Since the aminoimidazolines of the present invention contain three or more amino groups, besides the imidazoline ring group, they will require, ingeneral, more than one equivalent of acid for complete neutralization. We have found that a great improvement in anti-strip action is obtained by the addition of a minimum of one equivalent of acid per mole of imidazoline, and that some further improvement is usually obtained by neutralizing with two equivalents of acid. per mole. Higher degrees of neutralization, up to one equivalent of acid for each amino group and the imidazoline ring, may be employed, but will not show much greater anti-strip activity than that observed with the salts made with one or two equivalents of acid per mole.

The value of the aminoimidazoline salts as anti-strip agents is particularly apparent with carbonate aggregate rock consisting of limestone or dolomite or made up of mixtures of siliceous and limestone or dolomitic rock. While the aminoimidazolines, per so, are outstandingly eliective on siliceous aggregate, their wetting action on carbonate rocks is poor. The salts described above, however, we find to be very effective anti-strip agents for siliceous, limestone and dolomite aggregate. To illustrate this, unexpected and unusual effectiveness ofthese salts as anti-strip agents, the data of Table II are presented. These data were obtained from laboratory stripping tests run as those described above in connection with Table I, except that limestone aggregate was employed. A mid-continent MCI-3 asphalt was. used. For comparison, some resultsareshown for unneutralized aminoimidazoline.

TableH Salt. Added to M04 Asphaltby Percentage of Asphalt.

Combming- Stripped Gmsvof Wt. percent of Saltdn Acid per MG-B Asphalt (expressed Anunoimrdezm Acid 100: gms as Amtnolmidazoline) line- Amlnolmidazoline 0.2 0.3 0.4

Product of Ex- 100 100 95 4O 35 30 50 20 15 80 50 15 .do 132 25 5 DilIiiellt) Llno- 68 V 20. 6

e 0. D0 do 126- 5 3' Less" than 1.

Theseresults clearly show thegreatly improvedeflec: tiveness of the aminoimidazoline salt on limestone aggregate. I

In additionto. these testS,,:Similar ones were run with thesesaltsonVirginia silica and Merarnec River (lMiS; semi). gravel, two siliceousrocks. In. all cases the were as effective as the unneutralized amin oimidazoline when compared on the basis of aminoimidazoline concentrate in the asphalt.

The discovery of the effectiveness of these organic acid salts on carbonate aggregates actually constitutes an invention within an invention, and becomes of great practicable importance in the treatment of asphalts which are to be applied to aggregates containing significant amounts of carbonate rocks, such as limestone, dolomite, dolomitic limestone, and the like. Since, in practical work, stripping of as much as of the surface becomes important, the presence of as much as 5%, or possibly, even less, of carbonate rock in an aggregate constitutes a significant proportion. Reference in the claims to aggregate containing a significant amount of carbonate rock is intended to include aggregates containing 5% or more of such material.

While reference has been made particularly to the treatment of asphalt, it should be understood that the present process is applicable to and is intended to include treatment of equivalent bituminous materials, both natural and artificial, such as natural asphalt, blown asphalt, and similar products, and solutions, emulsions and dispersions of these products.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. An improved bituminous composition including a bituminous bonding agent, a solid aggregate containing a significant proportion of carbonate rock, and 0.05% to 2%, based on bituminous agent, of a salt of a polyaminoimidazoline of the formula:

where R is a hydrocarbon radical containing from 8 to 32 carbon atoms, m is the numeral 3 to 10, and X is selected from the class consisting of hydrogen and alkyl groups containing less than 4 carbon atoms; the acid group of said salt being selected from the class consisting of monocarboxy, detergent-forming acids, containing from 8 to 32 carbon atoms, and polymerized detergent-forming carboxy acids containing from 8 to 32 carbon atoms per carboxyl group; with the proviso that said salt contain at least one equivalent of carboxylic acid per mole of polyaminoimidazoline.

2. An improved bituminous composition including a bituminous bonding agent, a solid aggregate containing significant proportions of carbonate rock, and 0.05% to 2%, based on bituminous agent, of a salt of a polyaminoimidazoline of the formula:

N-OH,

where R is a hydrocarbon radical containing from 8 to 32 carbon atoms and m is the numeral 3 to 10; the acid group of said salt being selected from the class cons sting of monocarboxy, detergent-forming acids, containing from 8 to 32 carbon atoms, and polymerized detergentforming carboxy acids containing from 8 to 32 carbon atoms per carboxyl group; with the proviso that said salt contain at least one equivalent of carboxylic acid per mole of polyaminoimidazoline.

3. An improved bituminous composition including a bituminous bonding agent, a solid aggregate containing a significant proportion of carbonate rock, and 0.05% to 2%, based on bituminous agent, of a saltof apoly ainind-g imidazoline of the formula:

N-(JH: RO\

N-on,

2H4NH)m.H where R is the hydrocarbon radical of anacid selected from the class consisting of fatty acid and resin acids, and contains from 8 to 20 carbon atoms; and m is the numeral 3 to 10; the acid group of said salt being selected from the class consisting of monocarboxy, detergent-forming acids, containing from 8 to 32 carbon atoms, and

polymerized detergent-forming carboxy acids containing-- from 8 to 32 carbon atoms percarboxyl grou with the; proviso that said salt contain at least one equivalent of carboxylic acid per mole of polyaminoimidazoline.

4. An improved bituminous composition including a bituminous bonding agent, a solid aggregate containing a significant proportion of carbonate rock, and 0.05% to 2%, based on bituminous agent, of a salt of a polyamino:v

imidazoline of the formula:

(OsHtNH) m.H

where R is the hydrocarbon radical of tall oil acids, and m is the numeral 3 to 10; the acid group of said salt being selected from the class consisting of monocarboxy, detergent-forming acids, containing from 8 to 32 carbon atoms, and polymerized detergent-forming carboxy acids containing from 8 to 32 carbon atoms per carboxyl group; with the proviso that said salt contain at least one equivalent of carboxylic acid per mole of polyaminoimidazoline. 5. An improved bituminous composition including a bituminous bonding agent, a solid aggregate containing a significant proportion of carbonate rock, and 0.05 to 2%, based on bituminous agent, of a salt of a polyamino imidazoline of the formula:

/NCH2 RC N-OH,

where R is the hydrocarbon radical of rosin acids, and m is the numeral 3 to 10; the acid group of said salt being selected from the class consisting of monocarboxy, detergent-forming acids, containing from 8 to 32 carbon atoms, and polymerized detergent-forming carboxy acids containing from 8 to 32 carbon atoms per carboxyl group; with the proviso that said salt contain at least one equivalent of carboxylic acid per mole of polyaminoimidazoline. 6. An improved bituminous composition including a bituminous bonding agent, a solid aggregate containing a significant proportion of carbonate rock, and 0.05% to 2%, based on bituminous agent, of a salt of a polyaminoimidazoline of the formula:

NCH5 I Where R is the hydrocarbon radical of stearic acid, and m is the numeral 3 to 10; the acid group of said salt being selected from the class consisting of monocarboxy, detergent-forming acids, containing from 8 to 32 carbon atoms, and polymerized detergent-forming carboxy acids containing from 8 to 32 carbon atoms per carboxyl group; with the proviso that said salt contain at least one equivalent of carboxylic acid per mole of polyaminoimidazoline.

7. An improved bituminous composition including a bituminous bonding agent, a solid aggregate containing a where R is: the hydrocarbon radical of oleic acid, and m isthe numeral 3 to 10; the acidgroup of said salt being selected from the class consisting of monocarboxy, detergent-forming acids, containing from 8 to 32; carbon atoms, andjpolymerized detergent-forming carboxy acids containing from 8' to32'carbonv atoms percarboxyl group; with the proviso that said salt contain at least one equivalent: of carboxylic acid per mole-of polyaminoimidazoline.

8. An improved bituminous composition including a bituminous bonding agent, a solid aggregate containing asigni-ficant proportion of carbonate rock, and 0.05% to 2%, based on bituminous agent, of a salt oi a golyaminoimidazoline ofthe formula:

N-GH:

\ N-G'H:

((EaHiNH) "i where R is-thehydrocarbon radical of lauric acid,. and m. isthe numeral 3 to 1-0.; the acid group of said salt. being selected fromthe class consisting of monocarboxy, de-

tergent-forming acids, containing from 8 to 32 carbon;

atoms, and polymerized detergent-forming carboxy acids containing; from 8 to 32 carbonatoms per carboxyl group; with theiproviso that said saltcontain at least one. equiYalentof carbonylic acid per mole, of polyaminoimidazoline.

References Cited in the file of this patent UNITED STATES PATENTS 2,361,438 Mik cska ,Q c t. 31, 1 944 4 6,, e d et 3 -1+-.-V-V-r--.- F b- 9 3 2,468,163 Blair et al. Apr. 2,6 1949 

1. AN IMPROVED BITUMINOUS COMPOSITION INCLUDING A BITUMINOUS BONDING AGENT, A SOLID AGGREGATE CONTAINING A SIGNIFICANT PROPORTION OF CARBONATE ROCK, AND 0.05% TO 2%, BASED ON BITUMINOUS AGENT, OF A SALT OF A POLYAMINOIMIDAZOLINE OF THE FORMULA: 